<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div.window{
            position:absolute;
            width:300px;height: 200px;
            border:3px outset gray;
        }
        div.titlebar{
            position:absolute;
            top:0px;height: 18px;
            width:290px;
            background-color:#aaa;
            border-bottom:groove gray 2px;
            padding:3px 5px 2px 5px;
            font:bold 11pt sans-serif;
        }
        div.content{
            position:absolute;
            top:25px;
            height: 165px;
            width:290px;
            padding:5px;
            overflow: auto;
            background-color: #fff;
        }
        div.translucent{
            opacity: .75;
            filter:alpha(opacity=75)
        }
    </style>
</head>
<body>
<div class="window" style="left:10px;top:10px;z-index:10;">
<div class="titlebar">test window</div>
    <div class="content">
        1<br>2<br>3<br>1<br>2<br>3<br>1<br>2<br>3<br>1<br>2<br>3<br>
        1<br>2<br>3<br>1<br>2<br>3<br>1<br>2<br>3<br>1<br>2<br>3<br>
    </div>
</div>
<div class="window" style="left:75px;top:110px;z-index:20">
    <div class="titlebar">Another Window</div>
    <div class="content translucent" style="background-color:#ccc;font-weight: bold;">
        this is another window.Its <tt>z-index</tt> puts it on top of the other one.
        Css styles make its content area translucent,in browsers that support that.
    </div>
</div>
</body>
</html>